Thread wrapping apparatus

Abstract

In the thread wrapping apparatus disclosed herein a binder spindle is driven by control circuit at a speed corresponding to the operating frequency of a variable oscillator. First, second and third sets of drafting rolls which draw and feed a sliver of fibers to the binder spindle are driven by respective stepper motors through control circuits which operate each of the motors at a respective speed which is an individually preselectable proportion of the speed of the spindle.

What is claimed is: 
     
       1. Apparatus for forming a wrapped thread from a fiber supply, said apparatus comprising: a binder spindle;   a variable speed induction motor for driving said binder spindle at a preselectable speed;   a first control circuit means, including a variable oscillator and amplifier means, for operating said induction motor means at a speed corresponding to the operating frequency of said oscillator;   first, second and third sets of rolls for drawing said fiber, said third set of rolls having a pair of rolls downstream of said spindle;   a stepper motor means for each of said sets of rolls for driving the respective set of rolls at a respective preselectable speed; and   respective control circuit means for operating each of said stepper motor means, each of said respective control circuit means including a respective frequency scalar driven from said oscillator for operating the respective stepper motor means at a respective speed which is an individually preselectable proportion of the speed of said spindle motor.   
     
     
       2. Apparatus as set forth in claim 1 wherein said first control circuit means comprises a frequency scaler for generating an a.c. signal at a frequency which is a preselected proportion of the operating frequency of said oscillator, which a.c. signal is applied to said amplifier means for operating said induction motor at the frequency of said a.c. signal. 
     
     
       3. Apparatus for forming a wrapped thread from a fiber supply, said apparatus comprising: a binder spindle;   a variable speed induction motor for driving said binder spindle at a preselectable speed;   a first control circuit means, including a variable oscillator, and an amplifier driven by said oscillator to provide to said induction motor alternating current at the operating frequency of said oscillator for operating said spindle motor means at a speed corresponding to the operating frequency of said oscillator;   tachometer means driven by said spindle for generating a pulsatile signal at a frequency corresponding to the operating speed of said spindle;   first, second and third sets of rolls for drawing said fiber, said third set of rolls having a pair of rolls downstream of said spindle;   a stepper motor means for each of said sets of rolls for driving the respective set of rolls at a respective preselectable speed; and   respective frequency scaler circuit means, driven from said pulsatile signal, for providing to each respective stepper motor a step signal which is an individually preselectable proportion of the frequency of said pulsatile signal.   
     
     
       4. Apparatus as set forth in claim 3 wherein said first control circuit means includes a frequency scaler for generating an a.c. signal at a frequency which is a preselected proportion of the operating frequency of oscillator, which a.c. signal is applied is applied to said amplifier for operating said induction motor at the frequency of said a.c signal. 
     
     
       5. Apparatus for forming wrapped thread from a fiber supply, said apparatus comprising: a plurality of wrapping stations each of which includes,   a binder spindle,   spindle motor means for driving said binder spindle at a preselectable speed,   first, second and third sets of rolls for drawing said fiber, said third set of rolls having a pair of rolls downstream of said spindle,   a roll motor means for each of said sets of rolls for driving the respective set of rolls at a respective preselectable speed, and   respective control circuit means for operating each of said roll motor means at a respective speed which is an individually preselectable proportion of the speed of said spindle motor,   said apparatus further comprising:   a first control circuit means, including a variable oscillator, for operating a plurality of said spindle motor means at a speed corresponding to the operating frequency of said oscillator;   a second control circuit means, including a second variable oscillator, for operating at least one of said spindle motor means at a speed corresponding to the operating frequency of said second oscillator; and   respective switching means for connecting each of said spindle motor means to either said first control circuit means or said second control circuit means.   
     
     
       6. Apparatus for forming wrapped thread from a fiber supply, said apparatus comprising: a plurality of wrapping stations each of which includes,   a binder spindle,   spindle motor means for driving said binder spindle at a preselectable speed,   tachometer means driven by each spindle for generating a pulsatile signal at a frequency corresponding to the operating speed of the respective spindle,   first, second and third sets of rolls for drawing said fiber, said third set of rolls having a pair of rolls downstream of said spindle,   a stepper motor means for each of said sets of rolls for driving the respective set of rolls at a respective preselectable speed, and   respective frequency scalar circuit means, driven from the respective pulsatile signal, for operating each of said roll motor means at a respective speed which is an individually preselectable proportion of the speed of the respective spindle,   said apparatus further comprising: a first control circuit means, including a variable oscillator, for operating a plurality of said spindle motor means at a speed corresponding to the operating frequency of said oscillator;   a second control circuit means, including a second variable oscillator, for operating at least one of said spindle motor means at a speed corresponding to the operating frequency of said second oscillator; and   respective switching means for connecting each of said spindle motor means to either said first control circuit means or said second control circuit means.